An Application Of A New Class Of Nonlinear PID Controller On Synchrodrive Control

The background of the thesis is "Theory of Dynamic Precision synchronization Traverse and Research of Realization Methods for Linear Servo Dual Position Loops System (NO.50075057)", which is supported by National Natural Science Foundation of China.In this paper,we introduce a theory of Nonlinear PID control and put it in the system of motor's synchrodrive control.The method how to design a Nonlinear PID co trailer is also introduced.Compared with linear PID controller,this method is testified to be well.The linear permanent magnet synchronous motor(LPMSM) has avoided the effects of the mechanical transmission chains from rotary motions to linear ones, and has strong electromagnetism thrust, lower cost, small electrical time constant and rapid response etc., which becomes one of the best executive machines in the high-precision and micro-feed servo system. In this project, using LPMSM as driving parts in modern mechanical systems involved high-precision synchronized feed technology such as gantry-moving type milling machine is first proposed so as to bring their high-speed dynamic response ability into play for realizing dynamically synchronized feed.The innovative ideas in this paper is to replace the linear fixed-gain PID controller for a Nonlinear PID controller.Based on the step response curves of conventional control system,we analyze the ideal variety of three gains in different times and construct the simulated curves of proportional,intergral and derivative gain.The controllers has considered all sorts of imperceptible factors affecting the servo performances in a LPMSM servo system, which include the parametric uncertainties brought by the changes of the mobile mass, the dynamitic performance of the system and the size of input.To solve the problem of so many unknown parameters,we use transmit arithmetic to find the parameters which are fit for the system.to keep the robust and stable performance.The proposed control scheme has a rigorous theoretic base. The controllers designed not only guarantee the stability robustness and performance robustness of the system but also thetracking performance of the system. The simulation results show that the design is reasonable and effective.